MM on mine. QA1 on another car. MM is MUCH better quality; although the QA1 does have a little more room for headers, etc. But on these poor roads, I question the QA1 K member's strength if I were to hit one of the billions of gigantic pot holes, or heaven forbid hit another car. Actually on the '92 GT, I put MM K member on it and MM control arms; and MM struts & MM coil over kit & MM rack bushings. They got a lot of my (small) paychecks. But I like the quality. VERY well made. MM gives you lots of options for roll centers engine mounting location, etc etc. Rack position is another option; basically you choose how you're going to use the car. In my case, street car but I live in the hills and tend to be a little spirited going home (over a 1000' hill and then the twisties on the other side); so handling takes precedence over straight line pulls. MM is also slightly more weight but still lighter than a factory k member. So far the MM stuff has been on the car about 3 years now; and roughly a thousand miles. I don't drive it much (yet).
Had QA1 (LCAs and K) on a 78 Fairmont Futura street car with a 4 cylinder (turbo). The car was light to begin with and removing the stock K and putting the QA! stuff on it made it a little lighter. I was always questioning it's strength when pushing it a little too hard into a switchback or running down the highway and suddently running into/over a massive hole in the pavement that is basically invisible. There's plenty of those around here. It fit ok. I had to mess with the mounts a little because of the 4 cylinder (it is designed for 5.0/5.8). Was no big deal really and was also personal preference. I'm pretty sure it would have been fine with the stock location I just never really messed with it; wanted to get the engine back as far as I could. Also most of the K's are designed around 90-93 which 90-93 has larger wheel openings than 79-86 and obviously bigger than the Fairmont's openings were. I ran 25.5" tires on it and had minimal clearance issues; but perhaps a drag race application (28"?), you will want to take note of how far the LCA's are moved forward. They do this to improve caster among other things. Also the LCA pickup points are a little wider similar to the V8 87-93's which is no problem on a 87-93 but can cause issues on cars like the original foxes. I had barely 1/2" clearance between fender and tire, actually had to slot out the strut mount holes and do some other "adjusting" to get some camber, so that the tires had some clearance. It looked and worked fine for street duty. If using the V8 style wider LCA pickup points, such as most of the aftermarket K's use, you will want to certainly take note of your spindle choice since the 96-04 spindles move the wheels out a little wider than the 94-95. This applies if you are going to (or already have) 5 lug obviously. You can kinda get yourself into a pickle if not careful (BTDT). I think I put about 50,000 miles on that turd. One of the few cars I actually kinda miss.
PA looks nice but I have no direct experience with them.
I've used Granatelli and I have them (K and lca's) on another car (86 coupe drag car) and the quality was sub par. Lightweight but real cheesy. Nothing lined up either. Had to cut the mounts off and run motor plates which is fine because of the car's application. The plates are easier to deal with (to me) anyway since I'm used to them.
